1. Field of the Invention
This invention relates to an improved combustion cylinder construction for an oil space heater of the type for radiating heat rays, and more particularly to a combustion cylinder construction adapted to efficiently heat a room with heat rays radiated from a red-heated outer cylindrical member of a double combustion cylinder and with heat rays emitted from a white-yellow flame formed at a flame spreading means disposed above the combustion cylinder.
2. Description of the Prior Arts
In an oil space heater of the type for radiating heat rays, there have been conventionally used two kinds of combustion cylinder constructions. One of such constructions is adapted to burn a combustible gas in a space between outer and inner cylindrical members forming a double combustion cylinder to red-heat the cylindrical members and burn an incomplete combustion gas and a combustible gas contained in a combustion gas generated from the combustion cylinder at a flame spreading means disposed above the combustion cylinder to form a long white-yellow flame. In such conventional construction, a path for supplying a combustion air to the combustion cylinder is provided separate from a path for supplying a combustion air to the flame spreading means. That is, a combustion air supplied to the flame spreading means is guided from a space defined between the outer cylindrical member and a transparent heat-permeable cylinder surrounding the combustion cylinder through through-holes of the outer cylindrical member to the flame spreading means, whereas, a combustion air supplied to the combustion cylinder is introduced therein from through-holes of the outer and inner cylindrical members. Therefore, the air supplied to the flame spreading means prevents the outer and inner cylindrical members from being uniformly and efficiently red-heated, because it cools the cylindrical members.
More particularly, the conventional combustion cylinder construction of such type is constructed to carry out the mixing of a fuel oil vaporized from a wick with an air and the combustion of the fuel oil in the space between the inner and outer cylindrical members utilizing an air introduced from the through-holes of the cylindrical members, to thereby render the cylindrical members red-hot. Therefore, when an air supplied from the space between the outer cylindrical member and the heat-permeable cylinder through the through-holes of the outer cylindrical member to the flame spreading means flows in large amounts, the air cools the outer cylindrical member, thereby not allowing the member to be uniformly and efficiently red-heated. In addition, in order that the flame spreading means permits an incomplete combustion gas generated from the combustion cylinder to be stably burned, it is required to generate a strong draft toward the flame spreading means. However, in the conventional construction of such type, the draft causes a large amount of cold air to enter the space through the through-holes of the cylindrical members, resulting in the red-hot cylindrical members being cooled.
The other combustion cylinder construction conventionally used in an oil space heater of the type for radiating heat rays is constructed to guide a combustible gas generated in a space within a double combustion cylinder to the outer surface of an outer cylinder member to burn the gas on the outer surface of the outer cylindrical member, to thereby render the cylindrical member red-hot. Such conventional construction also is adapted to burn an incomplete combustion gas and a combustible gas contained in a combustion gas generated from the combustion cylinder at a flame spreading means disposed above the combustion cylinder. It is known in the art that such conventional construction allows the outer cylindrical member to be uniformly and efficiently red-heated, as compared to the construction as mentioned above.
In such conventional construction, it is known that it is desired to supply a combustion air for the flame spreading means from a space defined between the outer cylindrical member of the double combustion cylinder and a transparent heat-permeable cylinder surrounding the combustion cylinder through through-holes of the outer cylindrical member to the flame spreading means. However, the supply of a combustion air to the flame spreading means has a disadvantage that the air cools the red-hot outer cylindrical member to cause it to be nonuniformly and unstably red-heated, as in the combustion cylinder construction of the type mentioned above.
In addition, such conventional combustion cylinder construction has another disadvantage of causing an oil space heater having the construction incorporated therein to have a great height and a high center of gravity, thereby to render the oil space heater unstable particularly when the heater is tilted for the purpose of, for example, the igniting operation. In order to eliminate the disadvantage, a combustion cylinder construction has been proposed which is constructed to extend another transparent heat-permeable cylinder surrounding the flame spreading means to the lower portion of the oil space heater to surround the combustion cylinder as well. However, such construction has a defect of substantially attenuating heat rays generated from the red-hot outer cylindrical member because the heat rays must be passed through the two heat-permeable cylinders, to thereby decrease the heating efficiency of the oil heater.